<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
    <title>Document</title>
    <style>

    </style>
</head>
<body>
<div id="app">
<!--    <div :style="[boxStyle1,boxStyle2,boxStyle4]">test</div>-->

<!--    <div :style="[boxStyle2,boxStyle3]" >test</div>-->
    <input type="text" @input="changeMsg"/>
    <input type="text" @input="msg=$event.target.value"/>
    <h1>{{msg}}</h1>
</div>
<script>
    Vue.config.productionTip = false

    const vm = new Vue({
        el:'#app',
        data(){
            return{
                msg:'',
            }
        },
        methods:{
            changeMsg(e){
                this.msg = e.target.value
            }
        }
    })
</script>
</body>
</html>